The 'Pretty Woman' actress is usually queen of the beamers, but was knocked off her smile thrown by national treasure Cole.

Julia Roberts' mouth has an extraordinarily beautiful lip shape with a very wide, upturned top lip. When she smiles her mouth stretches wide displaying top and bottom teeth but her top lip retains this bias, making it a smile that projects both sensuality and a childlike sense of excitement and happiness.

It's the look of childlike spontaneity that makes this smile so infectious. It would be hard to look at it without smiling yourself.